Leasha. It must be hard to have such outright comments like that. My dh is not terribly supportive of me bfing either. He's made a few small comments like the Why do you want that Liam?!' or 'You're getting too big for that Liam!' when I get home from work and DS leaps on me. But nothing too major. Though just the other day I asked him to take a piccie of us having a feed and he was incredulous! 'Take a photo of you!!! Why??!' It was kinda funny at the time but when I though about it, well...
I don't really tell any friends or family I am still bfing DS. Although he's only 20mths old and still a baby, noone really understands. Many are less informed than us, though for you I daresay Shel would be just as informed as you are?
I guess I have no advice other than be upfront with her and tell her how it makes you feel when she says those things about yours and Jaz's bfing. It's not harming Shel in any way, why would it bother her so much?